ABSTRACT. The male of Bryophaenocladius carolinae sp. nov. is described and figured. The species can be separated from all other Neotropical species by having a hyaline, blunt triangular anal point, a comparatively small, sub-rectangular inferior volsella, gonostylus widened medially with an outer heel, R4+5 ending opposite to end of M3+4, setose squama and absence of comb on middle tibia and pseudospurs. A key to the adult males of the Neotropical Bryophaenocladius Thienemann is provided.

The genus Bryophaenocladius Thienemann is distributed worldwide, with the possible exception of Australasia. The genus is very rich with more than 100 species recorded (Du et al. 2011). Most species of Bryophaenocladius appear to be terrestrial or semi-terrestrial (Cranston et al., 1989) but Strenzke (1942) recorded immatures of B. subvernalis (Edwards) from two alpine lakes. The delimitation of this genus is difficult since there are exceptions for nearly all diagnostic characters, but in the last ten years several revisions clarify its systematicsand the topic is still in progress (Wang et al., 2001; 2004; 2006; Du et al., 2011). In this contribution, a new species of the genus Bryophaenocladius is described based on male specimens and the key to adult males of the genus for the Neotropical region by Wang et al. (2006) is updated.

MATERIAL AND METHODS

The specimens were collected with a sweep net. Microscope slides were made by clearing with 10% KOH; neutralization with glacial acetic acid; dehydration in 80%, 96%and 100% ethanol and mounting in Canada Balsam. Morphological measurements follow Sæther (1980) in μm rounded to the nearest 5 unless otherwise stated. Measurements are given as ranges followed by measurements of the holotype in square brackets. Comparisons with other members of the genus Bryophaenocladius were made from the original descriptions and revisions. In addition, the new species was compared with the holotype of Bryophaenocladius nidorum (Edwards) housed in the Natural History Museum (London, UK) and collection material of B. aestivus (Brundin), B. cf. astis (Roback), B. flavoscutellatus (Malloch) and B. pleuralis (Malloch) deposited in the Department of Natural History, Bergen Museum, University of Bergen, Norway. The holotypes of the species described by Dr. Manabu Sasa were studied from the National Museum of Nature and Science Tokyo (Japan), Type Specimen Database (http://www.type.kahaku.go.jp/TypeDB/diptera),except B. ikiheius Sasa et Suzuki which was not found in this database. The holotype and paratypes of Bryophaenocladius carolinae sp. nov. are housed in La Plata Museum, Argentina (MLP).

RESULTS

Bryophaenocladius carolinae sp. nov.

Diagnosis: The species can be separated from all other Neotropical species by the following combination of characters: anal point hyaline, triangular with blunt apex; inferior volsella comparatively small, sub-rectangular; gonostylus widened medially, with outer heel indicated; R4+5 ending opposite to end of M3+4, squama setose and comb on middle tibia and pseudospurs absent.

The genus Bryophaenocladius is one of the largest genera in the subfamily Orthocladiinae. The systematics andtaxonomy of this genus is based mainly on males with a few exceptions that are based on females and the knowledge of its immature stages is scarce. The variation in the taxonomic characters is large, mainly in the shape of the hypopygium. Wang et al (2006) pointed out that the species defined as belonging to Bryophaenocladius are based on a combination of characters and they also considered that probably this character variation could give rise to split the genus into several genera or subgenera in the future when the revision of the genus is completed. The new species here described was established after a comparison with the rest of the species of the genus from their original descriptions or from a revision, as well as after the study of their holotypes or collection material. In this way, 92 species of the genus Bryophaenocladius were compared with B. carolinae and studied in order to account for the variation in the taxonomic characters pointed out by Wang et al. (2006). The taxonomic characters were divided into two groups based on their importance in delimiting species. As a result, the most important characters used to define the Bryophaenocladius species are the shape of the anal point, the shape of inferior volsella, presence or absence of virga, shape of gonostylus, the presence and different degree of development of the crista dorsalis, presence or absence of the finger-like projection on palpomere 3 and wing punctuation. Other characters used in the species diagnosis, although less important, are the presence or absence of wing anal lobe, number of setae on R1 vein, different degree of development of acrostichal setae, length of Costal extension, length of megaseta, presence or absence of pseudospurs, presence or absence of a comb at apex of middle tibia, presence or absence of oral projections in sternapodeme, number of palpomeres and AR. Among the characters mentioned above as the most important, the character shape of anal point was found as a very good character since it has six well defined character states and only two particular character states. The characterstates found for this character are anal point long with rounded apex [e.g. B. aestivus (Brundin)]; anal point pointed triangular [e.g. B. flexidens (Brundin)]; anal point wide, trapezoidal [e.g. B. inconstans (Brundin)]; anal point bluntly triangular [e.g. B. scanicus (Brundin)]; anal point sharply triangular (e.g. B. parinberbus Wang et Du) and anal point subtriangular (e.g. B. usambarensis Andersen et Schnell). The other character states found were anal point small triangular (present in B. togatenuis Sasa et Okazawa) and anal point absent (present in B. ikiheius Sasa et Suzuki). The combination of characters anal point bluntly triangular and hyaline, gonostylus widened medially, virga present and finger-like apical extension on palpomere 3 present in Bryophaenocladius carolinae are shared with three species of the 92 species studied of the genus. The species B. digitatus Sæther is clearly distinguished from B. carolinae by the presence of a weak comb at apex of middle tibia, wing punctuation coarse and inferior volsella digitate with few curved setae dorsally. The species B. kobayashii Makarchenko et Makarchenko differs from B. carolinae by the presence of a rounded inferior volsella. The species B. xinglongensis Du et Wang is clearly distinguished from the new species here described by the presence of a not obvious and setose inferior volsella and R4+5 ending distal to end of M 3+4.

Key to males of the genus Bryophaenocladius from the Neotropical region (modified from Wang et al. 2006)

I greatly acknowledge Trond Andersen and Humberto Mendes for their hospitality, kindness and help during my visit to Bergen. In addition, I wish to thank Trond Andersen for his comments and suggestions on this work and his advice to improve my drawings. Also thanks to two anonymous reviewersfor their comments and suggestions that have improved this paper. Special thanks to Dr. Gustavo R. Spinelli, specialist of Ceratopogonidae of the Museo de La Plata, who examined the type of B. nidorum at the Natural History Museum in London.This paper was supported by grant PIP N° 0729 (CONICET).